As perhaps the most quotable and publicity-hungry head of a major company, Ryanair's Michael O'Leary has made an art out of generating newspaper coverage through supposed money-saving wheezes. Among the ideas mooted but somehow never implemented were a fat tax on bigger passengers and the introduction of standing-only tickets.

Now O'Leary is on the receiving end after a senior Ryanair pilot proposed a novel way for the budget carrier to save even more money: replace the chief executive with a low-paid cabin crew member.

Morgan Fischer's idea, outlined in a letter to the Financial Times, was put in a jocular fashion but contained a deadly serious message to O'Leary: as head of an airline, the one thing you don't speak about lightly is safety.

In an interview last week, O'Leary said he was seeking permission from aviation authorities to let Ryanair use just one pilot on short-haul flights as "the computer does most of the flying now", making co-pilots redundant.

Co-pilots are deemed a necessity in case something happens to the pilot. But O'Leary argued: "In 25 years with over about 10m flights, we've had one pilot who suffered a heart attack in flight and he landed the plane."

In typically provocative style, he ventured the idea that a flight attendant could fill in for the co-pilot given that this role was mainly to "make sure the first fella doesn't fall asleep and knock over one of the computer controls".

In a letter brimming with barely concealed distaste for the proposal, Fischer, who trains Ryanair pilots at its Marseille base, wrote: "As a Ryanair employee, I am aware of the company's desire to reduce costs whenever feasible, and in so doing, pass on these lower costs in the form of lower fares to the travelling public.

"I would propose that Ryanair replace the chief executive with a probationary cabin crew member currently earning about €13,200 (£11,000) net a year. Ryanair would benefit by saving millions of euros in salary, benefits and stock options. Further, there will be no need to petition either Boeing or governmental aviation regulators for approval to replace the CEO with a cabin crew member; as such approval would not be required."

Perhaps inevitably, Ryanair responded to the seemingly open challenge to its chief executive's authority with some slightly forced levity of its own.

"Michael thinks that cabin crew would make a far more attractive CEO than him – this obviously isn't a very high bar – so we are going to seriously look at the suggestion," a spokesman said. "After all, if we can train cabin crew to land the plane, it should be no problem training them to do Michael's job as well."

Separately, the head of the Irish Airline Pilots' Association, Evan Cullen, wrote to the FT querying O'Leary's assertion about the Ryanair pilot who suffered a heart attack, pointing out that the man in question was too gravely ill to land the plane and subsequently died. The pilot's family had asked for this to be clarified, he added.

The paradox is that in openly discussing his own demise as Ryanair boss O'Leary might, for once, be serious. In an interview with the Observer last weekend the 49-year-old argued that the airline might soon have to move away from surviving purely on low fares and vigorous PR efforts, thus needing a change in style at the top.

He said: "You will need a different management then. We won't need my dog and pony show, which is about generating publicity."